Added mkstemp function. Should use a secure random number generator.

include/stdlib.h

@@ -63,6 +63,10 @@ _PROTOTYPE( void qsort, (void *_base, size_t _nmemb, size_t _size,
 _PROTOTYPE( unsigned long int strtoul,
 			(const char *_nptr, char **_endptr, int _base)	);
 
+#ifdef _POSIX_SOURCE
+_PROTOTYPE( int mkstemp, (char *_fmt)					);
+#endif
+
 #ifdef _MINIX
 _PROTOTYPE( int putenv, (const char *_name)				);
 _PROTOTYPE(int getopt, (int _argc, char **_argv, char *_opts));

lib/stdio/Makefile

@@ -37,6 +37,7 @@ OBJECTS	= \
 	$(LIBRARY)(getchar.o) \
 	$(LIBRARY)(gets.o) \
 	$(LIBRARY)(icompute.o) \
+	$(LIBRARY)(mktemp.o) \
 	$(LIBRARY)(perror.o) \
 	$(LIBRARY)(printf.o) \
 	$(LIBRARY)(putc.o) \
@@ -152,6 +153,9 @@ $(LIBRARY)(gets.o):	gets.c
 $(LIBRARY)(icompute.o):	icompute.c
 	$(CC1) icompute.c
 
+$(LIBRARY)(mktemp.o):	mktemp.c
+	$(CC1) mktemp.c
+
 $(LIBRARY)(perror.o):	perror.c
 	$(CC1) perror.c
 

lib/stdio/mktemp.c

@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 1987, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)mktemp.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+static int _gettemp(char*,int*);
+
+mkstemp(path)
+	char *path;
+{
+	int fd;
+
+	return (_gettemp(path, &fd) ? fd : -1);
+}
+
+char *
+mktemp(path)
+	char *path;
+{
+	return(_gettemp(path, (int *)NULL) ? path : (char *)NULL);
+}
+
+static
+_gettemp(path, doopen)
+	char *path;
+	register int *doopen;
+{
+	extern int errno;
+	register char *start, *trv;
+	struct stat sbuf;
+	u_int pid;
+
+	pid = getpid();
+	for (trv = path; *trv; ++trv);		/* extra X's get set to 0's */
+	while (*--trv == 'X') {
+		*trv = (pid % 10) + '0';
+		pid /= 10;
+	}
+
+	/*
+	 * check the target directory; if you have six X's and it
+	 * doesn't exist this runs for a *very* long time.
+	 */
+	for (start = trv + 1;; --trv) {
+		if (trv <= path)
+			break;
+		if (*trv == '/') {
+			*trv = '\0';
+			if (stat(path, &sbuf))
+				return(0);
+			if (!S_ISDIR(sbuf.st_mode)) {
+				errno = ENOTDIR;
+				return(0);
+			}
+			*trv = '/';
+			break;
+		}
+	}
+
+	for (;;) {
+		if (doopen) {
+			if ((*doopen =
+			    open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
+				return(1);
+			if (errno != EEXIST)
+				return(0);
+		}
+		else if (stat(path, &sbuf))
+			return(errno == ENOENT ? 1 : 0);
+
+		/* tricky little algorithm for backward compatibility */
+		for (trv = start;;) {
+			if (!*trv)
+				return(0);
+			if (*trv == 'z')
+				*trv++ = 'a';
+			else {
+				if (isdigit(*trv))
+					*trv = 'a';
+				else
+					++*trv;
+				break;
+			}
+		}
+	}
+	/*NOTREACHED*/
+}
+
+/*
+ * $PchId: mktemp.c,v 1.3 1995/11/20 19:10:39 philip Exp $
+ */